title: Elevated factor VIII level and stroke in patients without traditional risk factors associated with cardiovascular diseases.
abstract: BACKGROUND
  Hemostasis is affected by interactions between physiological processes, including those connected with the coagulation system, whose essence is converting fibrinogen into fibrin. The role of factor VIII (FVIII) consists in activating factor X, which directly participates in the generation of thrombin, which is able to produce stable fibrin, which in turn forms blood clots. There are divergent opinions regarding the significance of high levels of FVIII in stroke pathogenesis.
  
  
  OBJECTIVE
  The aim of our study was to evaluate FVIII activity in individuals with cryptogenic stroke in order to determine a potential relationship between it and cerebral ischemia.
  
  
  METHODS
  NINE PATIENTS SUFFERING WITH STROKE WERE USED IN THIS STUDY: six women and three men aged 49-63 years. In all of the patients, the presence of known and potential risk factors for stroke had been excluded during previous diagnostic procedures. These patients accounted for 1.2% of the 719 people who suffered a stroke and were hospitalized in 2011 at the Stroke Unit. FVIII activity was examined in each of the nine qualified subjects within 1-2 months of the occurrence of stroke (the first test) and repeated (the second test) in five patients with abnormal results obtained from the first examination.
  
  
  RESULTS
  Increased activity of FVIII was found in 5 out of 9 patients. In patients with abnormal results, elevated FVIII was found in follow-up examinations in the 8th-10th month following stroke. Hemodynamic abnormalities in carotid or cerebral artery (presence of thrombus) were found in 3 of the 5 patients with increased FVIII levels. In the first 24 hours following stroke the neurological state of patients with abnormal FVIII was worse than individuals with normal FVIII activity. The patients with abnormal FVIII levels were found to be more disabled in the examination of self-dependence on the 90th day after stroke.
  
  
  CONCLUSIONS
  When searching for the causes of stroke, it is worth examining the coagulation system, including FVIII concentration, the abnormality of which may play a significant part in brain ischemia. More research is needed to determine the relationship between abnormal FVIII activity and stroke.
authors.affiliation: Stroke Unit, Department of Neurology, Medical University of Silesia, Professor Leszek Giec Upper Silesian Medical Centre, Katowice, Poland.
authors.forename: Anetta
authors.initials: A
authors.lastname: Lasek-Bal
authors.forename: Przemysław
authors.initials: P
authors.lastname: Puz
authors.forename: Zofia
authors.initials: Z
authors.lastname: Kazibutowska
keywords: cryptogenic stroke; factor VIII; hemostasis; risk factor